From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F025E81E1E for ; Fri, 6 Oct 2023 18:53:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233252AbjJFSxM (ORCPT ); Fri, 6 Oct 2023 14:53:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233272AbjJFSxL (ORCPT ); Fri, 6 Oct 2023 14:53:11 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B0D83CA for ; Fri, 6 Oct 2023 11:52:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1696618343; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DaHECssEKXoW7hu/fYmfrh3doxCibaAyOF7u4qbdM4E=; b=Bj2HIQJwkidOzL+qAVqipVvGrKq6V85hRBDBWyMg87S0H0X7fNliZNaUsspFd/OhBLV2Bu 28l4JCvxr8J3qLB0CbTKFUoI06hx2b6S8tUxmQVrfKlUrr0bJMojjiri8i9dFtEsrjVaDA bgKKZHBTvNOE/nScMHNl/93b9Irn1Os= Received: from mail-ej1-f70.google.com (mail-ej1-f70.google.com [209.85.218.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-680-e8GRssidO52sWI12CemTYA-1; Fri, 06 Oct 2023 14:52:22 -0400 X-MC-Unique: e8GRssidO52sWI12CemTYA-1 Received: by mail-ej1-f70.google.com with SMTP id a640c23a62f3a-9b822f5c156so208778966b.3 for ; Fri, 06 Oct 2023 11:52:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696618341; x=1697223141; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=DaHECssEKXoW7hu/fYmfrh3doxCibaAyOF7u4qbdM4E=; b=NjZXG0B+f7xfiDVuJTK3VADLsMd20HlvxRxv6l6IlVC5eUrzfLDblGcLJSXoiIK2f1 d6vzxunkNyuKLBcd4sDiwZoLj8ixbPXlVahFNsBGFMhfsflr+XTmCSxvD05JrbK+O2N4 HrNqtSc+VCaPCDNY7kZOIioEJt0jAMbsNZvxgkAs10sJCnHLKrWrLDeGeC5iiN5WAL6t ECf+q2DxKZyW6LPtnjQFf6/a0iTO9O1iVk3Fstysif+68Z3+olyTjhA2FYA1PMI47LkE QbbZHhuZn+RZb8iL97r+O62ozDgk9zWUhAs5AlNhQZWknXFSBU2gmOQAGI14GX/m9kpd DPxw== X-Gm-Message-State: AOJu0YyOtua+9vlEXJlUC7dCc9FHpLskhhZ75BorY29RaJenQaVzXlUM rypbo+dGsnEZzt7xi9aJ5QLoDR1tldyNrK5gsXeAX3HhSvRulzQKEiqsbXd4adlMwTFuWdIdmqm U0sHp6U3DBcTXspiygGh4WHohJAbbaTS+vq+bO1lt7pHdX6/tieERd08lj9pzRxVB/h+cy/vyNI ntcks= X-Received: by 2002:a17:906:74ce:b0:9ba:2a5:75c5 with SMTP id z14-20020a17090674ce00b009ba02a575c5mr2163790ejl.75.1696618341103; Fri, 06 Oct 2023 11:52:21 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFUGUCsuEIbPh9jWoEdfWB/Qb0RFrl18MRQsei0qGzW+4gIMWfP6mWpY/zlfNnJBryOxNnj4Q== X-Received: by 2002:a17:906:74ce:b0:9ba:2a5:75c5 with SMTP id z14-20020a17090674ce00b009ba02a575c5mr2163772ejl.75.1696618340817; Fri, 06 Oct 2023 11:52:20 -0700 (PDT) Received: from localhost.localdomain ([109.183.6.197]) by smtp.gmail.com with ESMTPSA id os5-20020a170906af6500b009b947f81c4asm3304741ejb.155.2023.10.06.11.52.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Oct 2023 11:52:20 -0700 (PDT) From: Andrey Albershteyn To: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, fsverity@lists.linux.dev Cc: djwong@kernel.org, ebiggers@kernel.org, david@fromorbit.com, dchinner@redhat.com, Allison Henderson Subject: [PATCH v3 03/28] xfs: define parent pointer xattr format Date: Fri, 6 Oct 2023 20:48:57 +0200 Message-Id: <20231006184922.252188-4-aalbersh@redhat.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231006184922.252188-1-aalbersh@redhat.com> References: <20231006184922.252188-1-aalbersh@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Allison Henderson We need to define the parent pointer attribute format before we start adding support for it into all the code that needs to use it. The EA format we will use encodes the following information: name={parent inode #, parent inode generation, dirent offset} value={dirent filename} The inode/gen gives all the information we need to reliably identify the parent without requiring child->parent lock ordering, and allows userspace to do pathname component level reconstruction without the kernel ever needing to verify the parent itself as part of ioctl calls. By using the dirent offset in the EA name, we have a method of knowing the exact parent pointer EA we need to modify/remove in rename/unlink without an unbound EA name search. By keeping the dirent name in the value, we have enough information to be able to validate and reconstruct damaged directory trees. While the diroffset of a filename alone is not unique enough to identify the child, the {diroffset,filename,child_inode} tuple is sufficient. That is, if the diroffset gets reused and points to a different filename, we can detect that from the contents of EA. If a link of the same name is created, then we can check whether it points at the same inode as the parent EA we current have. Signed-off-by: Dave Chinner Signed-off-by: Allison Henderson Reviewed-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_da_format.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/fs/xfs/libxfs/xfs_da_format.h b/fs/xfs/libxfs/xfs_da_format.h index fca622d43a38..307c8cdb6f10 100644 --- a/fs/xfs/libxfs/xfs_da_format.h +++ b/fs/xfs/libxfs/xfs_da_format.h @@ -862,4 +862,29 @@ static inline unsigned int xfs_dir2_dirblock_bytes(struct xfs_sb *sbp) xfs_failaddr_t xfs_da3_blkinfo_verify(struct xfs_buf *bp, struct xfs_da3_blkinfo *hdr3); +/* + * Parent pointer attribute format definition + * + * EA name encodes the parent inode number, generation and the offset of + * the dirent that points to the child inode. The EA value contains the + * same name as the dirent in the parent directory. + */ +struct xfs_parent_name_rec { + __be64 p_ino; + __be32 p_gen; + __be32 p_diroffset; +}; + +/* + * incore version of the above, also contains name pointers so callers + * can pass/obtain all the parent pointer information in a single structure + */ +struct xfs_parent_name_irec { + xfs_ino_t p_ino; + uint32_t p_gen; + xfs_dir2_dataptr_t p_diroffset; + const char *p_name; + uint8_t p_namelen; +}; + #endif /* __XFS_DA_FORMAT_H__ */ -- 2.40.1